928 resultados para Image analysis


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background. Ductal carcinoma in situ (DCIS) of the breast has been diagnosed increasingly since the advent of mammography. However, the natural history of these lesions remains uncertain. Ductal carcinoma in situ of the breast does not represent a single entity but a heterogeneous group with histologic and clinical differences. The histologic subtype of DCIS seems to have an influence on its biologic behavior, but there are few studies correlating subtype with biologic markers.Methods. The authors studied a consecutive series of 40 cases of DCIS and after its histologic categorization verified its relationship with ploidy using image analysis and analyzing estrogen receptor (ER), progesterone receptor (PR), p53 and c-erbB-2 expression using immunohistochemistry.Results. The three groups proposed according to the grade of malignancy were correlated significantly with some of the additional parameters studied, including aneuploidy and c-erB-2 expression. Aneuploidy was detected in 77.5% of cases of DCIS mainly in high and intermediate grade subtypes (100% and 80% vs. 35.7% in low grade) whereas immunoreactivity for c-erbB-2 was detected in 45% of cases of DCIS mainly in the high grade group. Expression of ER and PR were observed frequently in this study (63.9% and 65.7% respectively), but without correlation with the histologic subtype of DCIS, although we found a somewhat significant association between high grade DCIS and lack of ER. p53 protein expression was detected in 36.8% of these cases, but no relationship between this expression and histologic subtype or grading of DCIS was found.Conclusions. These results provide further evidence for the morphologic and biologic heterogeneity of DCIS. Besides histologic classification and nuclear grading, some biologic markers such as aneuploidy and c-erbB-2 expression constitute additional criteria of high grade of malignancy.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A small species of the genus Hepatozoon found in a specimen of Crotalus durissus terrificus from the Botucatu region, São Paulo State, Brazil is described. The morphologic alterations induced in the snake's erythrocytes by the presence of this parasite are described. Morphology and morphometric analyses were performed using the Qwin Lite 2.5 computerized image analysis system (Leica). The Hepatozoon possessed a small and short body (8.1+/-0.5 mum long and 3.8+/-0.4 mum wide), with round extremities. The cytoplasm varied from pale blue to basophilic and had no granulations. Its nucleus was large, occupied a large area of the cytoplasm, and was irregular in shape and not condensed. Despite its small size, this parasite induced important changes in the host cell. Total parasitemia observed was 56.6%.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Multivariate morphometrics and image analysis were used to determine the number of well-distinguished infrageneric taxa of reddish freshwater Audouinella in North America. Three distinct groupings were differentiated from 83 populations collected from Alaska and Labrador in the north to central Mexico and Jamaica in the south. These groupings were statistically related to seven type specimens. The following species were recognized: A. eugenea (SKUJA) JAO, A. hermannii (ROTH) DUBY [syn.: A. violacea (KUTZ.) HAMEL and its varieties, alpina (KUTZ.) RAB., dalmatica (KUTZ.) RAB., expansa (WOOD) SMITH, and hercynica (KUTZ.) KUTZ.] and A. tenella (SKUJA) PAPENFUSS. These species are separated based on dimensions of vegetative cells and monosporangia. A. tenella is found only in California, A. eugenea in warm, alkaline and high-ion waters of the tropical rainforest and desert-chaparral, while A. hermannii occurs widely from the boreal to south temperate and in waters with relatively low temperatures and ion content.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A computer program, PhotoLin, written for an IBM-PC-compatible microcomputer is described which detects linear features in aerial photographs, satellite images and topographic maps. The program accepts images saved to PCX files as input and applies noise correction and smoothing filters and thinning routines. The output consists of a skeleton containing the median lines of linear features which can be represented on a map. The branches of the skeleton can be broken into sections of constant length for which the mean orientations are obtained for the preparation of rose diagrams. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Objective. The aim of this study was to evaluate the castability of CP titanium and Ti-6Al-4V alloy castings into Rematitan Plus investment at three different mold temperatures.Methods. A nylon mesh pattern (20 mm with 64 squares and wire of 0.7 mm in diameter) was used for the castability testing. Initially, an image of the wax pattern was obtained by means of a digital camera and the total extension of filaments (mm) was then measured, using the Leica Qwin image analysis system. The mesh sprued was placed in the Rematitan Plus investment material and the castings were made in a Discovery Plasma machine at three different mold temperatures: 430 degrees C (control group), 480 degrees C or 530'C. Ten castings were made for each temperature. The images of the castings were analyzed (Leica Qwin) and the castability index determined by the number of the completely cast segments as a percentage of the wax pattern. Data were analyzed by two-way ANOVA and Tukey's multiple comparison test (a = 0.05) using materials and temperatures as discriminating variables.Results. The Ti-6Al-4V alloy (60.86%) presented a better castability index than CP Ti (48.44%) (p < 0.000001). For CP Ti, the temperature of 530 degrees C (23.96%) presented better castability than at other temperatures, 480 degrees C (14.66%) and 430 degrees C (12.54%), with no difference between them (p < 0.001). For Ti-6Al-4V alloy, there was a statistically significant difference among the three temperatures: 530 degrees C (28.36%) > 480 degrees C (19.66%) > 430 degrees C (15.97%) (p < 0.002).Significance. Within the limitations of this study, the increase in the mold temperature of the Rematitan Plus investment resulted in a better castability index for both materials, and Ti-6Al-4V presented a better castability index than CP Ti. (c) 2005 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Mechanical strength of polyethylene terephthalate (PET) fibres and polymethyl methacrylate (PMMA) matrix composites were studied with particular interest on the effects of oxygen and argon plasma treated fibres. PET. fibres were treated in a radio frequency plasma reactor using argon or oxygen for different treatment times to increase the interface adhesion. Fibre volume fraction was measured through digital image analysis. Elastic moduli resulted between 3 GPa for untreated to 6 GPa for treated composites. Tensile tests on PET fibres showed that plasma treatment caused a decrease in average tensile strength compared to untreated fibres. Fracture analysis confirmed the increase in interfacial adhesion due to plasma treatment. (c) 2004 Elsevier Ltd. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This article reports on a series of experiments with polyethylene terepthalate (PET) treated in a radio frequency plasma reactor using argon and oxygen as a gas fuel, for treatment times equal to 5 s, 20 s, 30 s, and 100 s. The mechanical strength modification of PET fibers, evaluated by tensile tests on monofilaments, showed that oxygen and argon plasma treatment resulted in a decrease in the average tensile strength compared with the untreated fibers. This reduction in tensile strength is more significant for argon plasma and is very sensitive to the treatment time for oxygen plasma. Scanning electron microscopy (SEM) used to analyze the effects of cold plasma treatment on fiber surfaces indicates differences in roughness profiles depending on the type of treatments, which were associated with variations in mechanical strength. Differences in the roughness profile, surveyed through an image analysis method, provided the distance of roughness interval, D-ri. This parameter represents the number of peaks contained in a unit length and was introduced to correlate fiber surface condition, before and after cold plasma treatments, and average tensile strength. Statistical analysis of experimental data, using Weibull cumulative distribution and linear representation, was performed to explain influences of treatment time and environmental effects on mechanical properties. The shape parameter, alpha, and density parameter, beta, from the Weibull distribution function were used to indicate the experimental data range and to confirm the mechanical performance obtained experimentally.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background: In recent years, important advances have occurred in the determination of diagnostic criteria for the disease diabetes mellitus and in new strategies for its treatment. The purpose of this research was to develop a new method for diabetes diagnosis by microscopic and cytomorphometric analyses of the oral epithelium. Methods: the smears were obtained from three distinct oral sites: buccal mucosa (cheek), tongue dorsum, and floor of the mouth in 10 control individuals and 10 type II diabetic patients. The oral smears were stained with Papanicolaou EA-36 solution. The nuclear (NA) and cytoplasmic (CA) areas were evaluated from 50 integral cells predominant in each oral site by the use of the KS 300(TM) image analysis system (Carl Zeiss, Germany), by which the cytoplasmic/nuclear ratio (C/N) was calculated. Results: the results showed that: (i) the epithelial cells of the diabetic group exhibited figures of binucleation and occasional karyorrhexis in all layers; (ii) the NA was markedly higher (P<0.05) in the diabetic group; (iii) the CA did not exhibit a statistically significant difference (P>0.05) between these two groups; and (iv) the C/N mean was 37.4% lower in the type II diabetic group. Conclusions: These results associated with clinical observations suggest that diabetes mellitus can produce alterations in oral epithelial cells, detectable by microscopy and cytomorphometry, which can be used in the diagnosis of this disease.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

In ascending aorta aneurysms, there is an enlargement of the whole vessel, whereas aortic dissections (ADs) are characterized by the cleavage of the wall into 2 sheets at the external half. We searched if alterations in collagen could be related to these diseases. Sections of aortas from 14 case patients with acute dissections, 10 case patients with aneurysms, and 9 control subjects were stained with picrosirius. Slides were analyzed under polarized microscopy to evaluate the structure of collagen fibers. The proportion of collagen was calculated in each half of the medial layer by color detection in a computerized image analysis system. Collagen appearance under polarized light was consistent with collagenolysis. The mean collagen proportions at the inner and outer halves, respectively, were 0.50 +/- 0.13 and 0.40 +/- 0.08 in the control group, 0.20 +/- 0.10 and 0.18 +/- 0.12 in the AD group, and 0.33 +/- 0.12 and 0.19 +/- 0.12 in the aneurysm group. The AD (P < .01) and control (P = .04) groups had less collagen at the external half, no difference was found in the aneurysm group (P = .71). In both halves, there was less collagen in the case patients than in the control subjects (all P < .01), but at the internal half, the decrease was significantly greater in the case patients with aneurysms than in those with dissections (P = .03; at the external half, P = .99). Aortic dissections and aneurysms show a decrease in collagen content that could be related to a weakness of the wall underlying the diseases, but the locations of the decrease differ: in dissections, it is situated mostly at the external portion of the media (site of cleavage), whereas in aneurysms, it is more diffuse, consistent with the global enlargement. (c) 2008 Elsevier B.V. All rights reserved.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background and objective: The purpose of this study was to analyze histologically the influence of autologous platelet-rich plasma on bone healing in surgically created critical-size defects in rat calvaria.Material adn Methods: Thirty-two rats were divided into two groups: the control group (group C) and the platelet-rich plasma group. An 8-mm-diameter critical-size defect was created in the calvarium of each animal. In group C the defect was filled by a blood clot only. In the platelet-rich plasma group, 0.35 mL of platelet-rich plasma was placed in the defect and covered by 0.35 mL of platelet-poor plasma. Both groups were divided into subgroups (n = 8) and killed at either 4 or 12 wk postoperatively. Histometric (using image-analysis software) and histologic analyses were performed. The amount of new bone formed was calculated as a percentage of the total area of the original defect. Percentage data were transformed into arccosine for statistical analysis (analysis of variance, Tukey, p < 0.05).Results: No defect completely regenerated with bone. The platelet-rich plasma group had a statistically greater amount of bone formation than group C at both 4 wk (17.68% vs. 7.20%, respectively) and 12 wk (24.69% vs. 11.65%, respectively) postoperatively.Conclusion: Within the limits of this study, it can be concluded that platelet-rich plasma placed in the defects and covered by platelet-poor plasma significantly enhanced bone healing in critical-size defects in rat calvaria.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This paper presents a method to recover 3D geometry of Lambertian surfaces by using multiple images taken from the same view point and with the scene illuminated from different positions. This approach differs from Stereo Photometry in that it considers the light source at a finite distance from the object and the perspective projection in image formation. The proposed model allows local solution and recovery of 3D coordinates, in addition to surface orientation. A procedure to calibrate the light sources is also presented. Results of the application of the algorithm to synthetic images are shown.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

With the objective of identifying predictors of fertility in bulls, the correlation coefficients of the midpiece length of bovine spermatozoa with semen traits and fertility were estimated. Data were obtained from semen samples of 50 crossbred bulls submitted to a progeny test. The midpiece length was determined in 40 midpieces of each bull through a image analysis system (Videoplan). Besides the physical traits before and after semen freezing, the oxygen consumption rate and the cytochemical activity index were observed. The correlation coefficients were low and non-significant (P> 0.05), indicating that the midpiece length is not a good predictor of fertility.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

By means of observation of hair fragments provoking paronychia and onycholysis in a barber, the authors performed a epidemiological investigation in others barbers/hair-dressers of Botucatu (SP), that showed a high frequency of die dermatosis.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This paper describes two solutions for systematic measurement of surface elevation that can be used for both profile and surface reconstructions for quantitative fractography case studies. The first one is developed under Khoros graphical interface environment. It consists of an adaption of the almost classical area matching algorithm, that is based on cross-correlation operations, to the well-known method of parallax measurements from stereo pairs. A normalization function was created to avoid false cross-correlation peaks, driving to the true window best matching solution at each region analyzed on both stereo projections. Some limitations to the use of scanning electron microscopy and the types of surface patterns are also discussed. The second algorithm is based on a spatial correlation function. This solution is implemented under the NIH Image macro programming, combining a good representation for low contrast regions and many improvements on overall user interface and performance. Its advantages and limitations are also presented.